Composite ringer



R. B, SHANCK.

COMPOSITE RINGER.

APPLICATION FILED MAYZI- I919.

1,366,423,. Patented Jan. 25, 1921.

2 SHEETS-SHEET l.

' an" non IIIIII lull INVENTOR jffi hmak BY WK ATTORNEY n. B. SHANCK. 'COMPQSITE RINQER. APPLlCATl-ON FILED MAUI. 1919.

Patented Jan. 25,1921.

' 2 SHEETS-SHEET 2 INVENTOR Y 135W BY Mg ATTdRNEY UNITED STATES PATENT OFFICE.

30v 3. sHAivcK, for KINGSTON, NE "$03K, ASSIGNOR 'ro AMERICAN TELEPHONE AND TELEGRAPH COMPANY,

A CORPORATION OF NEW YORK.

V COMPOSITE RINGER.

To all w/tomc't may conaem:

Be it known that I, ROY B. SHANOK, re-

sidin at Kingston, in the county of Ulster sociated therewith.

It has often been found desirable to associate with a transmission line coinposited- :for' both telephone and telegraph service,

arrangements for relaying ringing current transmitted over the line and such arrangements are particularly desirable for relaying r given later.

,In the arrangement of this invention, re-

' ringing current about repeater elements included in a line. It has been found in practice that with former relaying arrangements, the relayed ringing currentwould have a tendencyto leak back over the telegraph conductors which connect the two sections of the composited line independently of the relaying arrangements and cause the relaying arrangements to become locked in a working position, thereby causing a steady ring over the transmission line. Accordingly, it is one of the objects of this invention to provide means for relaying ringing current from one section of a-transmission line toanother section of the same line or other lines, and in associatingwith such relaying means arrangements which willinsure the restoration to normal ofthe relayr ing means upon the cessation of the original ringing current coming in over the line. A further object consists in'providing means for preventing the occurrence of false ringingover a transmission line connected'telegraphically with sections ofother lines when ringing current ls being transmitted over such sections. Other and further objects of the invention will be clear from the detailed description of the operation to. be

lay means responsive. to ringing 7 current transmltted over the line are bridged across themidpoints of windings'of the usual transr former associated with the repeater output circuits The operation of either of these ringing responsive relays will operate means on the other side of the repeater apparatus whereby ringing current will .be applied Patented Jan. 25, 1921.

Application filed May 21, 1919. Serial No. 298,654.

equally to the conductors associated with the outgoing section of'the transmission line and to the conductors associated with the network adapted to balance said line section. The two networks which balance the respective sectionsof the transmission line are interconnected by conductors having an impedance equal tothe telegraph conductors which interconnect the two line sections. By the above arrangements, any of the relayed ringing current which leaks back over the telegraph conductors to the incoming line and the conductors connected thereto will be opposed byan equal and opposite current which leaks back over the conductors interconnecting the networks and which tends to produce a potential equal and opposite thereto. These currents will accordingly neutralize each other and have no effect on the relay arrangements. I

The invention may be more fully under stood with reference to the accompanying drawings, in the Figure 1 of which is illustrated a preferred form of the circuit arrangements of the invention; in the Fig. 2 of which is illustrated a modification thereof.

Similar reference numerals have been used to denote like parts in both figures. For purposes of convenience, the relaying arrangements have been illustrated as associated with a cord circuit including the res peater elements 16 and 23 and adapted for interconnecting'the linesL L L and L although it will be understood that the arrangements of the invention might equally well be associated with a two-way two-element repeater directly connected to the lines or with othervmeans for connecting the lines telephonically. The repeater elements 16 and 23 are shown as of the mechanicaltype, although other types, such as the vacuum tube repeater, may be employed. Associated with the lines L L. L and L; are the artificial'lines or networks N N N and N adapted to balance the lines respectively.-

. The lines L and L are interconnected for telegraph purposes by the conductors land 2 in which are included the inductances 5 I and 6 which offer a'high impedance to telephone currents but do not interfere with the transmission of telegraph currents. The networks V and N are interconnected by conductors 3- and 4 in which are included'the inductances 7 and 8 which are similar to inductances 5 and 6. Included in thelines L and L; are Condensers, such as 9 and 10, which prevent telegraph currents from being transmitted to the telephone apparatus conheating the lines but which do not hinder the transmission of telephone currents thereto. Bridged across the lines L and l5 are the inductances 11 and 12, respectively, each having a tap to ground. These inductances' to ringing currents coming in over asection of the line. Controlled by relay 15 are the relays 28 and 29 upon the operation of which ringing current from the source 25 will be applied equally to the conductors leading to the outgoing section of the transmission line and t0 the network adapted for balancing said line section. Bridged across the midpoints of windings 19 and 20 is the relay 22 which is responsive to ringing currents coming in over a section of the line. Controlled by relay 22 are the relays 26 and 27 which serve to apply ringing current from the source 18 equally to the conductors leading to an outgoing, section of the transmission line and to the conductors leading to the network adapted for balancing said line section.

The operation of the arrangements illusj trated in Fig. l-is as follows: If the lines L and L, are interconnected by the cord cire cuit by inserting the plugs P and 1?, into the jacks J, and J respectively, ringing current coming in over the line L will be transmitted over the following circuit: from the tip conductor of line L,, tip contacts of jack J and plug P conductor 30, armature and contact of relay 26, conductor 31, upper portion of winding 13,. from the midpolnts of winding 13 through thewinding of relay 15 and thence to the mid aoi-nts of winding 12;

thence through the upper portion of winding 12, *conductor 32, contact and armatureof relay 26, conductor 33, ring contacts of plug P and jack J, to the ring conductorof line L As the'winding of relay 15 is included in the abovementioned ringing circuit, the relay 15 will be energized and will pull up its armature and close the following circuit:

from ground, armature and contact of relay 7 15, conductor 34, winding of relay 28, conductor 35, winding of relay 29 to battery and ground. The closing of this circuit will operate the relays 28 and 29. Upon the operation of relays 28 and 29 the source 25 of ring-- ing current will be connected over conductors 10 and 11 to conductors 37 and 39, respec' tively. At the same time ground will be applied to conductors 36 and 38. Accordingly ringing current from the source 25 will now be "transmitted out over the line L as 10llows: from source 25 over conductor 11, contact and armature of relay 29, conductor 39, lower ring contacts of plug P and jack J out over the ring conductor of line L, and back over the tip conductor of line L,, lower tip contacts of jack J and plug P conductor 38, armature and contact of relay '29 to ground. At the same time an equal ringing current from-the source 25 will be transmitted through the network N as follows: from source 25, over conductor 10, contact and armature of relay 28, conductor 37, upper ring contactsof plug P, and jack 5,, through the network N and back to the upper tip contacts of jack J -and plug P over conductor 36, armature and contact of relay 28, to ground. The portion of the ringing current from source 25 which was transmitted as described out over the line L may have a tendency to leak back over the telegraph conductors 1 and 2 to the line L and.

26, conductor 33, upper ring contacts of plug 1 P, and ack J rlng'conductor of line L andover telegraph'conductor2 to the tip conductor of line However at the same time the other portion of the ringing current from source 25' 'which was transmitted through the network 1 would have a tendency to leak back over telegraph conductors 3 and a to the ringing responsive relay 15 in over tip con the following manner: From the ring co1i-:. ductor associated WltlillQiTWOllZ N over conductor 3, tip conductorassociated with net work N lower tip contactszof jack J and plug P conductor 12, armature and contact of relay 27, conductor 13to the midpointof winding 12; from the midpoint of winding '12, through the winding of relay 15' to the j midpoint of winding 13; from the midpoint of winning 13, over conductor 14C, contact. and armature of relay 27, conductor 15, lower.

*ring contacts of plug P and. jack 3, and 7 over conductor l to the tip conductor associated with network N5. It will be seen that the direction of this last mentioned current which has a tendency to'leak back to the ring ing relay 15,over the telegraph conductors 3 and 4, is directly opposite to the direction of thecurrent which has a tendency to leak back to the ringing responsive relay 15 over- .winding 12, through the winding of relay'15 to the midpoint of winding 13. As these two currents originate from a common source 25 and are equal, and tend to flow through the windings of relay 15 in opposite directions,

and as each of these currents would be equally attenuated by the inductances 5, 6, 7 and 8, it will be seen that these currents will neutralize each other and accordingly will cause no interference with the ringing.

responsive relay 15.

In like manner, ringing current coming in oven-the line L, will operate the ringing responsive relay 22 which in turn controls the relays 26 and 27, whereby ringing current from the source 18 may be applied equally to conductors 30 and 33 associated with line L and to conductors 42 and 45 associated with the network N A portion of the ringing current thus transmitted in relay form out over the line L, may leak back over the telegraph conductors 1 and 2 to the line L and thence to the ringing responsive relay 22. However, this current would be neutralized by an equal current which would tend to leak back over the conductors 3 and 4 and would tend to llow through the ringing responsive relay 22 in an opposite direction and accordingly would cause no interference with the ringing responsive relay 22. As the operation would be substantially similar to that previously described with respect to ringing current coming in over the line L no fur ther description thereof will be given.

If a connection should be made between the lines L and L 'and at the same time a connection be made between the lines L and D, with cord circuits or arrangements employing former types of relaying means for ringing current, it will be seen that the relayed ringing current transmitted out over the line L might leak back over the telegraph conductors 1 and 2 to the line L and actuate the ringing means interconnecting the lines L and L and accordingly cause a false ring to result over line-L,. However if the lines L and L and the lines L and L are interconnected by cord circuits employing the relay means of this invention, the possibility of relayed ringing current leaking back from line L to line L over conductors 1 and 2 and operating the relaying means in the cord circuit interconnecting lines L and L will be obviated, as such ringing current would be neutralized in the cord circuit interconnecting lines L and L by an equal current leaking back over conductors 3 and 4- and tending to flow through the relaying means in anopposite direction. As the description of this operation would be'substantially the same as has been previously given, a further description of the circuits will be omitted.

In the arrangements illustrated in Fig. .2 the ringing responsive relays 1.5 and '22 con trol the relays 24: and 17 respectively. The relays 17 and 24 disconnect the output circuits of-the repeaters from the usual transformers and connect the source of ringing current to such transformers in a manner similar to the currents used for the transmission of speech. The currents which tend .to leak back over the telegraph conductors will neutralize each other in the same manner as previously pointed out with respect to Fig. 1. Accordingly no further description of the arrangements of Fig. 2 will be given.

While the invention has been disclosed in certain specific arrangements which have been deemed desirable, it is understood that it is not specifically limited to cord circuits 7 as illustrated, but may be employed with repeater apparatus permanently associated with the transmission line or with other means for connecting lines telephonically, and may be embodied in many and other widely varied forms without departing from the spirit of the invention, as defined in the appended claims.

lVhat I claim is:

1. A composite signaling system'comprising a pair of transmission lines, means to connect said lines for telephone purposes, means to connect said lines for telegraph purposes, a source of ringing current, means res onsive to ringing current transmitted over one of said lines to apply said source to the other line, whereby ringing current is transmitted over said line and over said means to connect said lines for telegraph purposes, and means to prevent the current transmitted over the latter path from affecting said responsive means.

2. In a telephone system, two line sec tions, repeaters for connecting said line sections, ringing relays associated with said line sections, telegraph conductors bridged around said repeaters; means responsive to ringing current coming in over one of said line sections for applying ringing current to the other line section and over said telegraph conductors to the first mentioned line section, thereby producing a potential difference tending to cause a current to flow in one direction through the winding of the ringing relay associated with said first mentioned line section, and means for simultaneously producing a potential difference tending to cause a current to flow in the opposite direction through said winding.

conductors connecting two of said lines and telegraph conductors connecting two of said networks, means to connect one of said last mentioned lines with a third line for telephone purposes, means associated with said connecting arrangements and responsive to current coming in over one of said lines interconnected for telephone purposes for applying ringing current to the other of the interconnected lines, whereby ringing current is transmitted over said telegraph conductors'to the second of said first mentioned two lines, means to connect said last mentioned line with another line for telephone purposes, means associated with said last mentioned connecting arrangements and responsive to current coming in over one of said last mentioned interconnected lines for applying ringing current to the other of said last mentioned interconnected lines,

and means to prevent the ringing current applied to'the lines by said first mentioned connecting arrangements from affecting the responsive means associated with said second mentioned connecting arrangements.

7 4. A telephone repeater system comprising two line sections, repeaters connecting said line sections, a normally disconnected source of ringing current associated with the output circuit of one of said repeaters, and means responsive to ringing current received over one of said line sections to disconnect said repeater from said output circuit and to connect said source to said ou put circuit. I

In testimony whereof, I have signed my name to this specification this 19th day of May 1919.

ROY B. SHANGK. 

